GB477055A - Process for the production of a series of coloured pigments from titanic acid derivatives - Google Patents

Abstract

A coloured pigment is prepared by calcining an intimate mixture of substances capable of forming two or more isomorphous salts or bivalent metals, of which salts at least one has titanium as the metallic element of its acidic component, the acidic element of the remaining salt or salts being at least one of the metals aluminium, iron and tin the substances being mixed in such proportions that stoichiometric quantities of the acidic and bivalent components are present, so that the process of calcination gives rise to the formation of the said isomorphous salts, and to the final formation of clearly defined solid solutions between these isomorphous salts. The ingredients of the starting mixture may be in the form of oxides, of compounds which are transformed into oxides by calcination, or, in some cases, of the finely-divided metals themselves. Specified constituents of such coloured pigments are zinc, magnesium, lead, cobalt, nickel, iron, manganese, copper, titanates, aluminates, ferrites, stannites and stannates. Specification 384,473 is referred to. The Specification as open to inspection under Sect. 91, describes also the preparation of coloured pigments consisting of solid solutions of two or more isomorphous titanates, and the use of chromium compounds as ingredients in the titanium pigments. This subject-matter does not appear in the Specification as accepted.